Enzymes are highly efficient environment-friendly catalysts, synthesized by living systems. They have significant advantages over chemical catalysts, of which the most important are specificity, high catalytic activity, ability to work at moderate temperatures, and the ability to be produced in large amounts. Enzymes production is a major and growing field of contemporary biotechnology. Tannin acyl hydrolase (EC 126.96.36.199) which is commonly referred to as tannase is one of the important hydrolytic microbial enzymes. Tannase is an industrially important enzyme and has several applications in various industries such as foods, animal feeds, cosmetics, pharmaceutical, chemical, leather industries etc. Realizing the importance of this enzyme, a comprehensive study focusing on its microbial production has been carried out. It aims to the isolation and screening of high tannase-producing fungi from environmental sources and statistical optimization of its production by the promising isolate using response surface methodology. This book includes all details of this study and its important results.